NRF52832 - Power spikes in eddystone example

[Martin]

Hi

I managed to get the eddystone example up and running on my custom board with NRF52832 (DCDC configuration). external HF, but no LF XTAL.

However, using SDK 17.0.2, I see spikes which hit 14mA current consumption.
What is the reason for this?

[Jared]

Hi there,

That doesn't quite look like an advertising event.

1. Can you describe your measurement setup?
2. Are you using the PPK2, in source mode or in ampere mode?
3. How is the board supplied, by USB? A laptop USB port is usually a  bit noisy, it's better to use for example a power bank to supply if you're using USB. 
4. Have you been able to replicate this on a development kit?

regards

Jared 

[Martin]

Hi Jared

it is very puzzling, as I see no reason why this is happening...

Checkout the screens.

Cheers

Martin

[Jared]

Hi there Martin,

I was able to reproduce your results with the PPK2 and after discussing it with other HW engineers I pretty sure that the spikes are introduced by the PPK2 itself. I wasn't aware of it, but this is actually a known issue. The spikes are caused by the PPK when it switches to a smaller measurement resistor because of the sudden current increase. Ideally the power profiler firmware should have filtered it out. Hopefully we'll get a Power Profiler fw fix for this in the future. In short, the 14-15 mA spikes are caused by the PPK2 and the nRF52 consumes less current, much more in line of what is estimated by the online power profiler.

I hope this explanation helps.

regards

Jared 

[Martin]

Hi Jared

thanks for verifying this.

Then I will move to a lab and try to measure the current with an osci again.

Cheers

Martin

[Jared]

Hi,

Great,

Keep me updated.

regards

Jared